Good quality Mod 1(M1) 5mm steel pinion gears in the most common sizes.

Terminology

Pinion: The smaller gear which goes on the motor.

Spur Gear: The larger gear which goes on the gearbox or drivetrain.

Sizing

Mod 1: The gap between each tooth, check this matches your spur gear.

5mm: The size of the hole, check this matches your motor shaft.

Gearing

Smaller Pinion/Larger Spur gear: Lower top speed, higher acceleration, lower motor temperature.

Larger Pinion/Smaller Spur gear: Higher top speed, lower acceleration, higher motor temperature.

-Motors may be geared according to desired performance, maximum gearing must be determined according to motor temperature.

-A safe maximum of 65c under worst case conditions is recommended to avoid motor damage.

-Conditions that may contribute to the highest motor temperature include: high ambient temperature, high tyre grip,

heavy and repeated acceleration and breaking, off road environments particularly grass and mud.

Installation

-Gear mesh must be set correctly to avoid damage particularly to plastic spur gears. There must be a small gap in the mesh between each gear.

The gap should be just enough that the gears run smoothly and play can be felt when moving either gear by hand.

-Low strength thread-lock must be used on the grub screw. Use heat from a soldering iron to deactivate threadlock before removal.

-Use of Hex-Plus bits/drivers to avoid stripping out grub screws is recommended.

-Where a grub screw strips out, remove motor and use a punch to gently and slowly hammer out motor shaft whilst supporting pinion in a vice.

Notes

-Appearance may vary from picture, does not affect functionality.

-If the size you require isn't listed, consider changing your spur gear to allow use of a more common size.